Psycological approach and analgesia are very important in paediatric dentistry. Sometimes the first is not enough and it is necessary the use of pharmacological methods. They are represented with sure and useful technique like "relative analgesia" with N2O/O2. The use of Caridex method is also very good in operative paediatric dentistry because there is not the necessity of local anesthesia with injection and the use of burns and drills. The AA. have connected together these two methods, and they present some very interesting clinical reports. With Caridex it's possible to remove only decayed dentine saving so the healthy dentine and reducing fear and stress in very young children. The association with relative analgesia permits to do a very early and global therapy in children also very young (24-36 months). The AA. have obtained a reduction of hemotivity, of odontogenous stress, and last but not least with this method there is the opportunity to avoid the general anesthesia.